Safety Grenade

Abstract

A grenade having electrical control means for arming the grenade in response to a predetermined free flight thereof and for firing an armed grenade in response to interruption of said free flight of the grenade, said control means having a safety time factor for preventing arming of the grenade in response to short periods of free flight. Means can also be provided for preventing unintentional operation of the grenade.

Parent Case Text

This application is a division of my copending application Ser. No. 847,852, filed Aug. 6, 1969, now U.S. Pat. No. 3,636,878.

Description

Heretofore, grenades were usually activated by a fuse which was normally ignited by a spring-operated striker and the fuse calibrated to set off the main charge at a predetermined interval of time thereafter. This has several disadvantages. Accidents can occur if a man should drop a grenade so as to accidentally ignite the fuse. Also, there is a danger that if thrown too soon, it can be picked up and thrown back before the fuse sets off the charge. To avoid this, it has been the practice of arming the grenade and holding it for a few seconds so that it will explode before it can be picked up and returned.

The present invention provides a grenade having a novel control for preventing the difficulties heretofore encountered. In carrying out the invention, the grenade is provided with a means for arming the grenade in response to predetermined free flight of the grenade and for firing the armed grenade in response to interruption of said free flight of the grenade.

A feature of the invention resides in the safety construction wherein the grenade is armed only after a predetermined interval of free flight and should the free flight cease prior to the arming, the control returns to normal position. Thus, if the grenade is dropped and/or accidentally placed in free flight for a short period of time, it will not become armed.

Another feature of the invention resides in the fact that the control means can be rendered inoperative to arm the grenade until a pin or other safety unit has been intentionally removed, thus preventing accidental arming of the grenade during storage or handling.

The control member can be an electrical control member and is highly effective in preventing accidental discharge of the grenade.

Other features and advantages of the invention will be apparent from the specification and claims when considered in connection with the accompanying drawings wherein:

The FIGURE is a sectional view showing a diagrammatic electrical circuit of an electrical control of the invention.

As shown in the drawings, the grenade has a frangible body 10, preferably metal, filled with a charge of explosive material 11, preferably a powder. A firing and control device comprises a plug 12 threaded into an opening 13 in the body 10 and has a tubular housing 14 threaded on the plug. The housing has a closed end 15 carrying a detonator or squib 516 which is located within the charge of explosive material to fire the charge when actuated.

In the form of the invention shown in the drawings an electrical control means is provided. As shown, a spherical cavity 32 in the head portion 33 of the plug 12 threaded in the body 10 is provided with an insulating liner 500 and supports two spaced electrical contacts 501, 502. Contact 501 is connected through a normally closed switch 503 to the + terminal of a battery 504 with the other terminal of the battery being grounded.

A safety pin 503a normally maintains the switch in open position until it is desired to fire the grenade at which time the pin 503a is withdrawn to permit the normally closed switch to complete the circuit therethrough.

The contact 502 is connected through a lead 505 to a resistor 506 and a capacitor 507 to ground. Also the lead connects through a resistor 508 to a unijunction transistor 509 and to a firing member or squib 516 to ground. The squib 516 is usually located in the housing 14 in inner wall 15, and battery, resistors, capacitor and transistor are usually potted into a single unit (not shown) disposed within the housing 14.

The liner 500 has a quantity of liquid conductor or electrolyte E stored therein and normally out of engagement with the contacts 501, 502 as shown in the Figure. However, when the grenade is in free flight the electrolyte will move to the dot-and-dash position and will close the circuit between contacts 501, 502.

With the circuit closed the current will flow through the resistor 506 and charge the capacitor 507 at a predetermined rate and providing the desired time delay for arming the grenade. The current will also flow through resistor 508 to provide a small bias on the transistor 509. When the free flight of the grenade is interrupted, after the grenade has been armed, the electrolyte E will return to normal position and open the circuit. This causes the bias current to become zero whereupon the capacitor discharges through its connection to the transistor 509 to ground and ignites the squib and fires the charge in the grenade.

Variations and modifications may be made within the scope of the claims and portions of the improvements may be used without others.

Claims

I claim:

1. A grenade device comprising a frangible body, a charge of explosive material within the body, means for firing the charge, and control means including an electric circuit having means for closing the circuit and arming the grenade in response to free flight of the grenade and means for opening the circuit and firing the grenade in response to interruption of said free flight.

2. A grenade device comprising a frangible body, a charge of explosive material within the body, means for firing the charge, and control means comprising a chamber having spaced contacts, said contacts being in an electrical circuit including a capacitor and a firing squib, means closing said circuit through said contacts to charge said capacitor to arm said grenade in response to a predetermined free flight of said grenade and opening the circuit through said contacts in response to interruption of said free flight, opening of said circuit causing the capacitor to be discharged and to fire the squib and discharge the charge.

3. The invention as defined in claim 2 wherein the means for closing said circuit through the contacts comprises an electrolyte in said chamber and normally out of engagement with said contacts, said electrolyte moving in response to free flight of the grenade to close said contacts.

4. The invention as defined in claim 2 wherein the electric circuit has a normally closed switch and the grenade has a removable safety pin to maintain said switch open until the pin is withdrawn upon a desire to fire the grenade.

5. The invention as defined in claim 2 wherein the charging rate of said capacitor provides a predetermined time delay to prevent inadvertent arming of the grenade.